I have a lot of soft kit (13th century), wool and linen that is heavily stained with WD40 and sweat. I cannot shift the grime using Woolite detergent. Can anybody recommend a good modern detergent that will not chew up the fabric (i.e. not biological to start with) but that is good to clean period clothes.

I'm not looking for something authentic to clean in front of the public, just to use at home in the washing machine.

When my wool kit gets oily, I soak it overnight with some Ecover washing stuff then run it through the machine with another dose of Ecover. Occasionally, it might need this doing twice but once through is usually more than enough.